Effect of Y403F mutation on adenylyl cyclase inhibition in whole-cell assays
| Agonist | n | EC50 | Inhibition | [R] | Wild-type EC50 | Wild-type inhibition |
|---|---|---|---|---|---|---|
| μm | % | pmol · dm−2 | μm | % | ||
| Acetylcholine | 3 | 1.7–4.9 | 71.3 ± 4.9 | 5.0–17 | 0.014–0.07 | 80.0 ± 3.6 |
| Carbachol | 6 | 1.3–37 | 70.8 ± 5.1 | 5.0–33 | 0.036–0.5 | 65.4 ± 5.1 |
| Oxotremorine M | 5 | 0.6–4.9 | 74.4 ± 3.7 | 5.0–23 | 0.0087–0.28 | 76.2 ± 2.5 |
| Pilocarpine | 4 | 10–110 | 19–43 | 5.0–23 | 3.4–15 | 37–62 |
EC50 values for the inhibition of adenylyl cyclase activity are reported as a range that varies inversely with [R]. Maximal inhibition is reported as mean ± standard deviation except for pilocarpine, for which inhibition was variable and increased with increasing [R] as in wild-type. These values are compared with the wild-type values for the same range of receptor site densities observed in wild-type-expressing CHO cells from data previously reported (20).